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机械化保护性耕作技术与传统耕作技术相比,可减少土壤风蚀、水蚀,减少土壤流失和抑制农田扬尘的功效,提高土壤肥力和抗旱能力;能明显提高旱区粮食产量、降低农业生产成本、改善生态环境、促进农业可持续发展等特点.主要应用于干旱、半干旱地区农作物生产. 相似文献
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我国是主要的干旱国家之一,干旱、半干旱及半湿润偏旱地区的面积占国土面积的52.5%.由于过度的开垦及不适当的耕作方式,使得旱区农业持续发展受到水土流失、风蚀沙化等严重影响。植被破坏与土地沙漠化愈来愈快,沙尘暴发生的频率愈来愈高.因此.为了控制沙尘暴,保护生态环境,改变旱区农业的面貌,需进一步推广保护性耕作技术。国外实践证明保护性耕作技术能保护农田.减少农田扬沙.减少土壤风蚀和水蚀。保护性耕作打破传统的铧式犁耕作方式,而采用免(少)耕的耕作方式,来实现旱地农业的可持续发展。 相似文献
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一、什么是保护性耕作 保护性耕作技术是通过少耕、免耕、化学除草技术措施的应用,尽可能保持作物残茬覆盖地表,减少土壤水蚀、风蚀,实现农业可持续发展的一项农业耕作技术。 二、保护性耕作的技术内容 保护性耕作技术有利于旱区保水保土,增产增收和保护环境。主要内容是用秸秆残茬保护土地、减少耕作、免耕播种、化学 相似文献
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针对山西省晋东南地区传统的玉米耕作使得土壤风蚀和水蚀严重、土壤有机质下降和耕层变浅等问题,研究了玉米保护性耕作技术,对保护生态环境、发展可持续农业具有重要意义。 相似文献
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农业保护性耕作技术是当今国际上先进的农业生产技术.实施以残茬覆盖和免耕、少耕为主要内容的机械化保护性耕作,可以减少地表径流,避免土壤流失,降低土壤风蚀,增加土壤有机质含量,改善耕地肥力及理化性状,是实现保土、保水、保肥和保持生态环境的重要措施,是旱作农业实现可持续发展的重要途径. 相似文献
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我国农业生产环境脆弱,水资源紧缺,现有耕地94970khm^2,旱区约占60%,主要分布在日照长、温差大、富有农业生产潜力的北方和中西部地区。传统的耕作方式使土壤由于过度耕作而造成地表裸露,耕地退化,生态环境恶化。特别是近年来北方尘暴、沙化愈来愈烈,极大制约了农业的发展。迫切需要大力推广应用保护性耕作技术。对农田实行免耕少耕、残茬覆盖、生物覆盖、尽可能减少土壤耕作,减少土壤风蚀、水蚀,提高土壤肥力和抗旱能力。 相似文献
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介绍彰武县在推广保护性耕作技术中所采用的主要技术模式及作业质量,分析在项目实践中遇到的相关问题,并提出解决方法.通过田间试验,对比分析保护性耕作与传统耕作模式下的土壤理化指标及产量情况,证明实施保护性耕作可以改善土壤品质,实现增产增收,促进农业可持续发展. 相似文献
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本文针对乌拉特中旗开展保护性耕作的现状,积极探索出适合该地区旱作农业保护性耕作的技术模式及实施保护性耕作采取的措施,阐明实施保护性耕作技术是实现旱作农业可持续发展的有效途径。 相似文献
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《Journal of Agricultural Engineering Research》1998,69(3):249-254
A model to represent the discolouration of dried powder of carrots as a function of temperature was developed. Two types of carrots, Asian and European, containing large amount of lycopene and β-carotene, respectively, were tested. The dried powder was stored under an atmosphere with O2and at three different temperatures, 5,20 and 35°C. The surface colour of the powder was monitored during storage by a Hunter colour ratioa/b. In the proposed model, the rate of oxidation was assumed to be represented by the product of the fraction of concentration of oxidized pigment at arbitrary time and a specific rate of oxidation of pigment. The rate parameters in the proposed model were calculated by fitting the experimental data with smooth curves by trial and error at the end of the induction period but before discolouration took place. The frequency constant and activation energy, expressing the temperature dependence of the rate parameters, were expressed by the Arrhenius relation. The simulation results of a Hunter colour ratioa/bof dried powder at 25°C showed good agreement with the experimental data, suggesting that the proposed model was effective for the prediction of discolouration of dried powder of both types of carrot. The use of the induction period in the manner described may enable the shelf life of dried powder to be predicted. 相似文献
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感官检验棉花的品级,这是农村常见的一种检测手段.它的一个主要特点就是存在不确定性.这是由于检验员的品级检验水平存在一定的差异,其中有很多因素制约着检验的结果.文章对影响感官检验结果的因素进行了系统的分析. 相似文献
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从灾害经济学的角度探讨了城镇供水优化调度的必要性和可能性,认为在缺水不可避免的情况下,对供水进行优化调度可以减小缺水带来的损失,产生较好的减灾效益,特别是可以大大减小严重干旱的灾害效应。并根据水资源的特性,提出了缺水损失的计算模式以及优化调度的原则和方法。 相似文献
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The fractional outflow rate of water from the rumen, measured as the rate of disappearance of the chromium complex of ethylenediamine tetra-acetic acid, was related to a number of dietary factors. A multiple regression equation was derived which expressed fractional outflow rate as a function of the intakes of dry matter, ash, acid-detergent fibre and crude protein.The data analysed consisted of 243 observations for sheep on 59 diets, including forage, concentrate and mixed diets. The ranges covered by the data were: fractional outflow rate 0.7–3.6 day?1; dry matter intake 560–1400g/day; ash 4–30%, acid-detergent fibre 7–41%, crude protein 5–26 % of dry matter; there were no observations for sheep of less than 34 kg liveweight.The equation accounted for 56·3 % of the total variance. Between-sheep variance could not be calculated for the whole of the data but was undoubtedly substantial since, for a sixth of the data, it was known to account for 38 % of the total variance. 相似文献